Structural elements such as rods, tubes, and beams are normally made by casting, extruding, or rolling techniques to produce plastic or metal tubing, sheets, rods, beams, and the like. These structural elements normally comprise a single material which is chosen for its combination of physical properties, e.g., strength and weight, as well as corrosion resistance, color, and texture. Plastic molding and extrusion procedures have provided the possibility of preparing plastic structural elements with selected combinations of physical properties, chemical properties, color, texture, etc. Fiber reinforcement of plastic materials has provided much higher physical strength properties than the plastic material alone could offer. In general, these fiber reinforced materials are made by extruding through a die a plastic melt having continuous strands of fiber distributed therein. The extrudate is then solidified in the form of a continuous rod, beam, or strand and can be cut into whatever length is desired for use. The disadvantages of the prior art procedures are (1) that the extrudate can not be made into a curved or non-linear article, and (2) the surface properties at the extrudate cannot be changed from that inherent in the extruded plastic.
It is an object of this invention to provide a novel structural element of fiber reinforced plastic material. It is another object of this invention to provide methods for manufacturing such structural elements. Still other objects will be apparent from the more detailed description which follows.